scholarly journals Optical detection of the susceptibility tensor in two-dimensional crystals

2021 ◽  
Author(s):  
Michele Merano ◽  
Zhemi Xu ◽  
Davide Ferraro ◽  
Annamaria Zaltron ◽  
Nicola Galvanetto ◽  
...  
Keyword(s):  
Plane Surface ◽  
Three Dimensional ◽  
Single Layer ◽  
Optical Response ◽  
Optical Measurements ◽  
Two Dimensional ◽  
Reliable Determination ◽  
Susceptibility Tensor ◽  
Two Dimensional Materials ◽  
Out Of Plane

Abstract The out-of-plane optical constants of two-dimensional materials have proven to be experimentally elusive. Owing to the reduced dimensionality of a monolayer, optical measurements have limited sensitivity to these properties, which are hidden by the optical response of the substrate. Therefore, there remains an absence of scientific consensus on how to correctly model these materials. Theoretical descriptions span from isotropic three-dimensional slabs to two-dimensional surface currents with a null out-of-plane surface susceptibility. Here we perform a smoking gun experiment on the optical response of a single-layer two-dimensional crystal that addresses these problems. We successfully remove the substrate contribution to the optical response of these materials by a step deposition of a monolayer crystal inside a thick polydimethylsiloxane prism. This allows for a reliable determination of both the in-plane and the out-of-plane components of the monolayer surface susceptibility tensor. Our results prescribe one clear theoretical model for these types of material. This work creates opportunities for a precise characterization of the optical properties of two-dimensional crystals in all the optical domains such as the nonlinear response, surface wave phenomena or magneto-optical Kerr effect. Our assay will be relevant to future progresses in photonics and optoelectronics with 2D materials.

scholarly journals Optical detection of the susceptibility tensor in two-dimensional crystals

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhemi Xu ◽  
Davide Ferraro ◽  
Annamaria Zaltron ◽  
Nicola Galvanetto ◽  
Alessandro Martucci ◽  
...  
Keyword(s):  
Single Layer ◽  
Optical Response ◽  
Optical Measurements ◽  
Two Dimensional ◽  
Reliable Determination ◽  
Susceptibility Tensor ◽  
Two Dimensional Materials ◽  
Out Of Plane

AbstractThe out-of-plane optical constants of monolayer two-dimensional materials have proven to be experimentally elusive. Owing to their reduced dimensionality, optical measurements have limited sensitivity to these properties which are hidden by the optical response of the substrate. Therefore, there remains an absence of scientific consensus on how to correctly model these crystals. Here we perform an experiment on the optical response of a single-layer two-dimensional crystal that addresses these problems. We successfully remove the substrate contribution to its optical response by a step deposition of a monolayer crystal inside a thick polydimethylsiloxane prism. This allows for a reliable determination of both the in-plane and the out-of-plane components of its surface susceptibility tensor. Our results prescribe one clear theoretical model for these crystals. This precise characterization of their optical properties will be relevant to future progresses in photonics and optoelectronics with two-dimensional materials.

Piezoelectricity in Monolayers and Bilayers of Inorganic Two-Dimensional Crystals

2013 ◽  
Vol 1556 ◽  
Author(s):  
Karel-Alexander N. Duerloo ◽  
Mitchell T. Ong ◽  
Evan J. Reed
Keyword(s):  
Density Functional ◽  
Electromechanical Coupling ◽  
Three Dimensional ◽  
Single Layer ◽  
Elastic Model ◽  
Two Dimensional ◽  
Functional Theory ◽  
Symmetry Properties ◽  
Electromechanical Effects ◽  
Out Of Plane

ABSTRACTThe symmetry properties of many inorganic two-dimensional monolayer crystals make them piezoelectric, whereas their three-dimensional parent crystals are not. The emergence of piezoelectricity in the single-layer limit points toward intriguing electromechanical effects and applications in the single- or few-layer regime. We use density functional theory to calculate the piezoelectric coefficients of BN, MoS2, MoSe2, MoTe2, WS2, WSe2 and WTe2. These coefficients are found to be comparable to, and in some cases greater than those of commonly used wurtzite piezoelectrics. The centrosymmetry of a BN bilayer prevents a piezoelectric effect for this structure. However, by developing an elastic model, we find that the bilayer exhibits an unusual electromechanical coupling to the curvature, similar to that of a bimorph. A BN bilayer is found to amplify the constituent monolayers’ in-plane piezoelectric displacements by factors on the order of 103-104 into out-of plane deflections.

scholarly journals Polarization-sensitive photodetectors based on three-dimensional molybdenum disulfide (MoS2) field-effect transistors

Nanophotonics ◽  
2020 ◽  
Vol 9 (16) ◽  
pp. 4719-4728
Author(s):  
Tao Deng ◽  
Shasha Li ◽  
Yuning Li ◽  
Yang Zhang ◽  
Jingye Sun ◽  
...  
Keyword(s):  
Molybdenum Disulfide ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistors ◽  
Three Dimensional ◽  
Polarized Light ◽  
Optical Field ◽  
Two Dimensional ◽  
Polarization Ratio ◽  
Two Dimensional Materials

AbstractThe molybdenum disulfide (MoS2)-based photodetectors are facing two challenges: the insensitivity to polarized light and the low photoresponsivity. Herein, three-dimensional (3D) field-effect transistors (FETs) based on monolayer MoS2 were fabricated by applying a self–rolled-up technique. The unique microtubular structure makes 3D MoS2 FETs become polarization sensitive. Moreover, the microtubular structure not only offers a natural resonant microcavity to enhance the optical field inside but also increases the light-MoS2 interaction area, resulting in a higher photoresponsivity. Photoresponsivities as high as 23.8 and 2.9 A/W at 395 and 660 nm, respectively, and a comparable polarization ratio of 1.64 were obtained. The fabrication technique of the 3D MoS2 FET could be transferred to other two-dimensional materials, which is very promising for high-performance polarization-sensitive optical and optoelectronic applications.

scholarly journals Homogeneous 2D and 3D alignment of cardiomyocyte in dilated cardiomyopathy revealed by intravital heart imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoshi Masuyama ◽  
Tomoaki Higo ◽  
Jong-Kook Lee ◽  
Ryohei Matsuura ◽  
Ian Jones ◽  
...  
Keyword(s):  
Heart Failure ◽  
Dilated Cardiomyopathy ◽  
Cardiac Dysfunction ◽  
Three Dimensional ◽  
Single Layer ◽  
Specific Pattern ◽  
Two Dimensional ◽  
Heart Imaging ◽  
Novel Method ◽  
2D And 3D

AbstractIn contrast to hypertrophic cardiomyopathy, there has been reported no specific pattern of cardiomyocyte array in dilated cardiomyopathy (DCM), partially because lack of alignment assessment in a three-dimensional (3D) manner. Here we have established a novel method to evaluate cardiomyocyte alignment in 3D using intravital heart imaging and demonstrated homogeneous alignment in DCM mice. Whilst cardiomyocytes of control mice changed their alignment by every layer in 3D and position twistedly even in a single layer, termed myocyte twist, cardiomyocytes of DCM mice aligned homogeneously both in two-dimensional (2D) and in 3D and lost myocyte twist. Manipulation of cultured cardiomyocyte toward homogeneously aligned increased their contractility, suggesting that homogeneous alignment in DCM mice is due to a sort of alignment remodelling as a way to compensate cardiac dysfunction. Our findings provide the first intravital evidence of cardiomyocyte alignment and will bring new insights into understanding the mechanism of heart failure.

High-yield fabrication of suspended two-dimensional materials for atomic resolution imaging

RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 76273-76279 ◽  
Author(s):  
Jaehyun Han ◽  
Jun-Young Lee ◽  
Jeongun Choe ◽  
Jong-Souk Yeo
Keyword(s):  
Three Dimensional ◽  
Atomic Resolution ◽  
High Yield ◽  
Two Dimensional ◽  
Two Dimensional Materials ◽  
Resolution Imaging

Two-dimensional (2D) atomic crystals are very interesting materials due to their unique properties, which are significantly different than those observed in conventional three-dimensional (3D) materials.

scholarly journals Tip-Based Nanomachining on Thin Films: A Mini Review

2021 ◽  
Author(s):  
Shunyu Chang ◽  
Yanquan Geng ◽  
Yongda Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Data Storage ◽  
Three Dimensional ◽  
Maintenance Cost ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current State ◽  
Two Dimensional Materials

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.

scholarly journals Band-gap tuning and optical response of two-dimensionalSixC1−x: A first-principles real-space study of disordered two-dimensional materials

2017 ◽  
Vol 96 (5) ◽  
Author(s):  
Banasree Sadhukhan ◽  
Prashant Singh ◽  
Arabinda Nayak ◽  
Sujoy Datta ◽  
Duane D. Johnson ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Optical Response ◽  
Real Space ◽  
Two Dimensional ◽  
Two Dimensional Materials ◽  
Band Gap Tuning

Can a three-dimensional composite really provide better mechanical performance compared to two-dimensional composite under compressive loading?

2018 ◽  
Vol 38 (2) ◽  
pp. 49-61 ◽  
Author(s):  
M Tarfaoui ◽  
M Nachtane
Keyword(s):  
Mechanical Performance ◽  
Split Hopkinson Pressure Bar ◽  
Compressive Loading ◽  
Three Dimensional ◽  
Woven Composites ◽  
Two Dimensional ◽  
Hopkinson Pressure Bar ◽  
Out Of Plane ◽  
Split Hopkinson ◽  
Pressure Bar

A series of split Hopkinson pressure bar tests on two-dimensional and three-dimensional woven composites were presented in order to obtain a reliable comparison between the two types of composites and the effect of the z-yarns along the third direction. These tests were done along different configurations: in-plane and out-of-plane compression test. For the three-dimensional woven composite, two different configurations were studied: compression responses along to the stitched direction and orthogonal to the stitched direction. It was found that three-dimensional woven composites exhibit an increase in strength for both: in-plane and out-of-plane tests.

Irrotational flow past bodies close to a plane surface

1971 ◽  
Vol 50 (3) ◽  
pp. 481-491 ◽  
Author(s):  
E. O. Tuck
Keyword(s):  
Asymptotic Expansion ◽  
Numerical Computation ◽  
Potential Flow ◽  
Close Agreement ◽  
Plane Surface ◽  
Three Dimensional ◽  
Ground Surface ◽  
Two Dimensional ◽  
General Shape ◽  
Irrotational Flow

A theroetical analysis is given for potential flow over, around and under a vehicle of general shape moving close to a plane ground surface. Solutions are given both in the form of a small-gap asymptotic expansion and a direct numerical computation, with close agreement between the two for two-dimensional flows with and without circulation. Some results for three-dimensional bodies are discussed.

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